Deflection yoke assembly and mounting



Feb. 24, 1970 H. c. COLLIE, JR

DEFLECTION YOKE ASSEMBLY AND MOUNTING Filed 001:. 18, 1967 FIG4 \INVENTOR HOMAH C. COLLIE JR ATTORNEYS.

United States Patent O 3 497,843 DEFLECTION YOKE A SSEMBLY AND MOUNTIN GHomah C. Collie, Jr., Arcade, N.Y., assignor t Motorola, Inc., FranklinPark, Ill., a corporation of Illinois Filed Oct. 18, 1967, Ser. No.676,166 Int. Cl. H01f 7/00 US. Cl. 335-210 8 Claims ABSTRACT OF THEDISCLOSURE The assembly includes a yoke encircling a cathode ray tubeand a cover for the yoke with rearwardly extending fingers each having acammed outer surface. The assembly also includes a ring having a cammedinner surface to mate with the outer surfaces of the fingers and adaptedto be rotated to draw the fingers against the neck of the cathode raytube.

BACKGROUND OF THE INVENTION After mounting a deflection yoke on acathode ray tube, it is usually necessary to make final adjustments byaxially moving the yoke along the tube neck. Once the position isselected, mounting devices located both at the front and at the back ofthe yoke are tightened to secure the yoke to the cathode ray tube. Inpresent day assemblies, such devices are generally annular strap-typeclamps with a screw positioned in apertures in the ends of the clamp.The strap encircles projections on the yoke assembly so that tighteningof the screw secures the yoke to the cathode ray tube. However, thesescrews must be tightened with a tool such as a wrench or a screwdriverand because of the position of the cathode ray tube within its cabinet,it is often difficult and therefore time consuming to mate the tool withthe screw. In addition, the strap has a width on the order of inch tomake good mechanical connection to the projections which extend about /2inch or more. In a color television receiver Where additional componentssuch as convergence apparatus and purity magnets must be mounted on thecathode ray tube neck, neck space is at a premium. In the past, in orderto accommodate the widths of the strap and projections, the choice hasbeen to increase the neck length and make the cabinet that much deepedor else place the additional components closer to the assembly therebylimiting the amount of available axial room necessary to properlyposition the deflection yoke.

Summary of the invention It is therefore an object of this invention toprovide a device for mounting a deflection yoke on a cathode ray tubewhich requires no tools for tightening the same.

Another object is to provide a deflection yoke assembly and mountingtherefor which requires a minimum axial space on the neck of the cathoderay tube.

In practicing a preferred form of the invention, a deflection yokeassembly includes a set of windings mounted on a support having acentral opening for encompassing the neck of a cathode ray tube. Thefront end of the support is secured to the flared portion of the cathoderay tube. A cover mounted on the rear end of the support has a centralopening to encompass the neck of the cathode ray tube. A plurality ofrearwardly extending fingers integrally attached to the cover each havecammed outer surface. A clamp member having a corresponding plurality ofcammed inner surfaces mates with the outer surfaces of the fingers andis adapted to be rotated with respect to the fingers to tighten theassembly to the neck of the cathode ray tube.

3,497,843- Patented Feb. 24, 1970 Description of the drawings FIG. 1 isa side view of a cathode ray tube with the means for mounting thedeflection assembly;

FIG. 2 is an end view on an enlarged scale of the mounting means of FIG.1;

FIG. 3 is a view taken along the line 3-3 of FIG. 2;

FIG. 4 is a view taken along the line 4-4 of FIG. 2; and

FIG. 5 illustrates another embodiment of the invention.

Detailed description of the preferred embodiments Referring now to FIG.1, the cathode ray tube 10 has a funnel or flared portion 12, a neckportion 14 and a front panel or viewing screen (not shown). A yokeassembly 18 has a support structure 20 encircling the neck portion 14and part of the flared portion 12. A set of windings represented bynumeral 22 is mounted adjacent the annular front end portion 24 of thesupport 20 and serves to deflect the electron beams which travel fromguns mounted in the neck portion 14 towards the viewing screen. Actuallythe windings extend rearwardly over most of the inner and outer surfacesof the support 20. An iron core (not shown) conforming to the shape ofthe support 20 overlies the windings on the outer surface. A mountingring 25 has a plurality of integral feet 26 which extend at an angleequal to the angle of taper of the flared portion 12 of the tube 10.Two-sided adhesive tape 28 mounted on one side of the feet 26 is used toadhere the feet to the surface of the flared portion 12. The annularfront end portion 24 of the support structure 20 fits inside the ring 25which acts as a jig to select the position of the assembly 18 so it isconcentric with the neck portion 14 of the tube. After the finalposition is selected, a clamp 30 is used to tighten the ring 25 aboutthe portion 24 to draw the yoke assembly 18 tightly against the cathoderay tube 10.

The support 20 also includes a rear end 32 which is generallyrectangular in shape and is formed with rearwardly extending sides toform a housing for wires connected to the windings 22. A base portion orcover 34 is also generally rectangular in shape and has dimensionsslightly increased over the dimensions of the rear end 32 and istherefore adapted to be snap fitted onto such rear end to protect theconnecting wires and the windings 22. Integrally connected to the cover34 are a plurality of fingers 36 extending axially rearwardly from thecover. A clamp 38 tightens the fingers 36 to the neck portion 14 tosecure the deflection yoke assembly 18.

After the television receiver incorporating the cathode ray tube 10 isfully assembled, the clamps 30 and 38 are loosened and the deflectionyoke assembly 18 is axially moved to optimize color purity and the like.After a position is selected, the clamps 30 and 38 are tightened to lockthe assembly 18 in the desired position.

To more fully appreciate the means which secure the deflection yokeassembly to the neck portion 14 of the cathode ray tube 10, reference ismade to FIGS. 24. The cover 34 has a flat surface 39 and an annularinclined surface 40 which slopes toward the center and toward the flaredportion 12 of the cathode ray tube 10 and terminates in a plurality offingers 36= integrally joined to the surface 40 and extending axiallyrearwardly. The inner diameter of the central opening formed by fingers36 is slightly less than the diameter of the neck portion 14 of thecathode ray tube 10 so as to fit snugly thereon and to compensate forthe tolerances which may exist in the diameter of the neck portion. Eachof the fingers 36 has a portion 42 adjacent the inclined surface 40 anda portion 44 extending from the portion 42 and away from the inclinedsurface 40. Each of the portions 42 has a generally annularly shapedouter surface and the outer surface of the portion 44 of each of thefingers has a cammed shape. The fingers 36 have a length so as to extendonly slightly beyond the flat surface 39 of the cover 34 and thereforethe cover will require a minimum of axial space on the neck portion 14of the cathode ray tube 10.

The clamp member 38 has a generally annular outside periphery and has aplurality of cammed surfaces 46 on its inside periphery to correspond innumber and shape to the cammed surface 44 o nthe fingers 36 of the cover34. A pair of tabs 48 and 50 preferably molded into the cover 34 formgrooves with the inclined surface (see FIG. 4). The clamp 38 has a pairof notches 52 and 54 which are respectively aligned with the tabs 48 andS and inserted thereover. When the clamp 38 is rotated, it will belocated between the tab 48 and the inclined surface 40 on one side andbetween the tab 50 and surface 40 on the other side and therefore willbe retained by the cover 34. Because the outer surface of the portion42. of the fingers 36 is annular and because the outer surface of theportion 44 o fthe fingers is cammed, a shoulder or ridge 55 is formed attheir junction substantially parallel to the flat surface 39. The ridge'55 provides a seat for the clamp 38. Preferably the fingers 36 areslightly inclined so as to tilt radially outwardly away from the flaredportion 12 of the tube 10 when the cover is inserted on the neck portion14. This forms a slight depression in the portions 44 of the fingers 36for preventing slippage of the clamp 38 off of the fingers The clamp 38also has a pair of tabs 56 and 58 which may be grasped for rotating theclamp 38. Preferably the tabs are bent so as to be parallel to the mainbody portion of the clamp 38 but in a higher plane, with the main bodyportion positioned within the inclined surface 40 and with the tabs 56and 58 overlying the flat surface 39 of the cover 34. Accordingly, themounting assembly is a compact unit and requires a minimum of axialspace on the neck portion 14 of the cathode ray tube.

After the deflection yoke assembly 18 is axially adjusted to the properposition, and the clamp 30 on the front end of the support 20 istightened, the clamp 38 is rotated with respect to the fingers 36 sothat the cammed surface of the clamp 38 presents an increasing radialforce against the cammed surfaces of the fingers 36 to draw the sameagainst the neck portion 14 and secure the deflection yoke assembly 18.It should be noted that such tightening procedure is accomplished veryquickly and efficiently without the use of a tool such as a screw or nutdriver. In present day sets, in order to tighten the assembly, a screwor the like must be rotated which, first requires time to position thetool on the screw and, second requires additional time to rotate thescrew. The use of tools is undesirable for another reason, that is, themetal tool may touch the high voltage terminal on the cathode ray tubewhich may be on the order of 25 kilovolts and therefore quite dangerousto the serviceman servicing the television receiver.

A further form of the invention is illustrated in FIG. where the clamp30, the associated screw and the mounting ring are eliminated. This isaccomplished by forming a plurality of resilient feet 60 integrally withthe front end 24 of the support 20 which feet have a slope slightly lessthan the slope of the flared portion 12 of the cathode ray tube 10.'When the deflection yoke assembly 18 is positioned on the neck portion.14 and is forced up against the flared portion 12, the resiliency inthe feet 60 force the assembly 18 rearwardly. The clamp 38 may betightened at the desired position to preclude further axial or radialmovement of the assembly 18. This absence of radial movement will beattained as long as the feet or some portion thereof engage the flaredportion 12 to provide the rearward bias of the yoke assembly 18.

What has been described, therefore, is an improved mounting assembly fora deflection yoke which requires no tools to tighten the yoke to thecathode ray tube and requires a minimum of axial space on the neck.

What is claimed is:

1. Apparatus for mounting a deflection yoke on the neck portion of acathode ray tube having an axis, which apparatus includes incombination, a base portion having a central opening adapted to beslipped on the neck portion of the cathode ray tube, said base portionhaving means for attachment to the deflection yoke, a plurality ofaxially extending fingers joined to said base portion, each of saidfingers having a cammed outer surface, a clamp member having acorresponding plurality of cammed inner surfaces to mate with the outersurface of said fingers, whereby positioning said clamp member on saidfingers and rotation of said clamp member with respect to said fingersdraws said fingers against the neck portion to prevent movement of thedeflection yoke with respect to the cathode ray tube.

2. In a cathode ray tube assembly having a cathode ray tube with a neckportion and a flared portion and an axis parallel to the neck portion, adeflection yoke disposed on the neck portion of the cathode ray tube andhaving a front end and a rear end, mounting apparatus including incombination, a base portion having a central opening adapted to beslipped on the neck portion of the cathode ray tube and against the rearend of the deflection yoke to exert an axial force towards the flaredportion to bias the deflection yoke against the flared portion, aplurality of axially extending fingers joined to said base portion, eachof said fingers having a cammed outer surface, a clamp member having acorresponding plurality of cammed inner surfaces mating with the outersurfaces of said fingers, whereby rotation of said clamped member withrespect to said fingers draws the fingers against said neck portion tocause said base portion to maintain the bias of the deflection yokeagainst the flared portion.

3. A deflection yoke assembly adapted to be mounted on a cathode raytube having a neck portion and a flared portion, which assembly includesin combination; a set of windings, a support for the windings havingfront and rear ends and a central opening for encompassing the neckportion of the cathode ray tube, means to secure the front end of thesupport to the flared portion of the cathode ray tube, a cover membermounted on said rear end of said support and having a central-opening toencompass the neck portion of the cathode ray tube, a plurality ofrearwardly extending fingers attached to said cover member, each of saidfingers having a cammed outer surface, a clamp member having acorresponding plurality of cammed inner surfaces mating with the outersurface of said fingers, whereby rotation of said clamp member withrespect to said fingers draws said fingers against the neck portion andprevents movement of the yoke assembly with respect to the cathode raytube.

4. The deflection yoke assembly set forth in claim 3 wherein said meansto secure the front end of the support comprises a plurality ofresilient feet attached to said front end for hearing against saidflared portion to spring bias said support rearwardly, whereby rotationof said clamp member substantially prevents movement of the assemblywith respect to the cathode ray tube.

5. The deflection yoke assembly set forth in claim 3 wherein said clampmember has a pair of tabs for rotating said member.

6. The deflection yoke assembly set forth in claim 3-, wherein saidcover member has a pair of tabs molded therein to form a space betweensaid tabs and said cover member, and wherein said clamp member has apair of notches aligned with said tabs for slipping said clamp memberover said tabs and into said space, whereby rotation of said clampmember causes retention of the same by said tabs.

7. The deflection yoke assembly set forth in c aim 3 wherein said covermember has a depressed portion surrounding said fingers, said covermember having an outer portion, said fingers having an axial length toextend slightly beyond the plane of said outer portion, wherein saidclamp member has a main body portion which includes the cammed innersurface and tab means for rotating the same and raised above said mainbody portion, said main body portion being positioned in said depressedportion to provide a compact mounting assembly.

8. The deflection yoke assembly set forth in claim 3 wherein saidfingers have a forward outer surface which is annular and a rearwardouter surface which is cammed to form a ridge between said surfaces,with said ridge forming a seat for said clamp member.

References Cited UNITED STATES PATENTS GEORGE HARRIS, Primary ExaminerUS. Cl. X.R.

